| 摘要 |
<p>The quality and strength of a spot weld can be correlated to a drop in resistance during the fusion process. Rather than measuring this resistive drop at the welding electrodes by attaching external sensing means thereto, a control system makes use of the phenomenon that a resistive drop also causes a change in the total load power factor further resulting in a change to the current extinction angle of a weld half cycle. By determining the amount of increase or decrease that has occurred in the current extinction angle during a weld or a group of welds, a basis for the control of the welding beat is obtained. The power factor monitoring and control system is used for controlling the quality of a spot weld made in the automotive industry on assembly line welders.</p> |
